1 Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, Texas, USA Charles.darkoh@uth.tmc.edu.
2 Microbiology and Molecular Genetics Program, University of Texas Graduate School of Biomedical Sciences, Houston, Texas, USA.
3 Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, Texas, USA.